They're newer enlargers so the lens mounts on the Omegas should be the same, most likely 39mm.
You could also look for a dichro head for your B600. I don't recall if they made one or not though.
The 23 C is a nice enlarger, 1/2 the price & you get to look at it. It has the dichro head on it and looks to be in good shape, I believe you would be way ahead of the game with it.
I believe that one has the power supply built into the head. If one of the cables has a funky multiple contact on it it WILL need an additional PS. If both cables have a grounded three prong plug it doesn't.
The pic seems to show a negative carrier too.
The only caution would be to check that it's working before you haul it home.